288 Kansas Academy of Science. 



insects under observation, unavoidably entered into the experi- 

 mental work, so that the reason for any change in the course 

 of the lines of the insects could not be definitely attributed to 

 the effect of one element alone, even such as temperature, with- 

 out being proved by corroboration. One important factor 

 which was apt to produce abnormal effects arose from the em- 

 ployment of artificial measures for breeding purposes. The 

 responsibility of such circumstances demanded watchful con- 

 sideration, and any unusual manifestation of the bugs needed 

 to be conclusively understood and verified with regard to all 

 features involved. 



Therefore, as many questions remain open to dispute, no 

 positive significance of results can be declared without sub- 

 stantistion by further experiments for one or more years. 

 Hence progress in determining the reasons for effective results 

 must necessarily be slow in order to be reliable. 



The artificial condition under which the bugs were bred cor- 

 responded as nearly as possible with natural conditions, but 

 still differed materially because confinement of the bugs was 

 imperative. More constant and substantial provisions were 

 required for studying these insects under close observation 

 than could be offered them in nature. In consequence the 

 bugs were afforded the best of advantages for their sustenance 

 and propagation. 



The most noticeable feature which was evinced during the 

 summer in the existence of the bugs was a falling off in the 

 number of young bugs born every day. From the standard 

 daily production of eight young bugs by one adult the birth 

 rate declined to three or four young ones per day, seldom being 

 more, but often less, and rarely none at all. This reduction of 

 one-half or more in the usual multiplication of the bugs could 

 not be proved to have been caused by hot weather when other 

 weighty reasons demand consideration, especially with regard 

 to the effects of artificial conditions and continuous breeding 

 from one generation to another without the intervention of 

 males. However, this curtailment of the reproductive ca- 

 pacity was partly redeemed by a tendency of the bugs to attain 

 an early maturity and begin bearing young ahead of the regu- 

 lar time. Such irregularity was shown in a number of in- 

 stances, requiring only five or six days instead of the ordinary 

 period covering eight days. Maturing in advance of the usual 

 time hastened the appearance of consecutive generations. 



